/Engine/Plugins/Runtime/RigVM/Source/RigVMDeveloper/Public/RigVMCompiler/RigVMAST.h
Default constructor (protected so that only parser can access it)
FRigVMExternalVarExprAST ( const [FRigVMASTProxy](API\Plugins\RigVMDeveloper\RigVMCompiler\FRigVMASTProxy) & InPinProxy )